The present invention relates to a dispenser head designed to be mounted on the plunger stem of a dispenser device, such as a pump or a valve, for dispensing a fluid substance. The dispenser head serves as an actuating member on which action is taken by means of a finger for the purpose of actuating the pump or the valve. The fluid substance is delivered from the pump or from the valve through the plunger stem on which the spray head is mounted. In order to enable the fluid to be dispensed, the dispenser head is provided with a dispensing orifice which communicates with the plunger stem via an outlet duct. When a liquid such as a perfume is to be dispensed, the dispenser head can incorporate a spray jet-forming insert making it possible to spray the liquid.
A conventional spray head is shown in FIG. 1 and is designated by the overall numerical reference 10. The head 10 comprises a body 2 which is cylindrical in shape. At its top end, the body 2 forms a wall 27 against which a finger is pressed to actuate the pump or the valve. In addition, the body 2 defines a peripheral skirt 28 which extends downwards from said wall 27 over a certain height. The height of the peripheral skirt 28 is determined in part by the height of the stroke of the plunger stem of the pump or valve on which the head is mounted. For reasons of aesthetic appearance, the skirt 28 must extend to the level of the fixing ring for fixing the pump or the valve to the container, in order to hide the plunger stem. Thus, when the pump or valve is actuated, the peripheral skirt 28 of the dispenser head 10 engages above the fixing ring. The height of the peripheral ring 28 is thus directly dependent on the type of pump or valve on which the spray head 10 is mounted.
In addition, the body 2 is provided with a recess 21 serving to receive the top end of the plunger stem. The recess 21 communicates with one or more outlet ducts 22. The one or more ducts 22 open out in an annular space formed around a core 23 that is formed integrally in the body 2. The recess thus formed by the annular space serves to receive a spray jet-forming insert 4 which is engaged by force in said annular space. Conventionally, the insert 4 is provided with a dispensing orifice, and when a fluid substance such as perfume is to be dispensed, the insert 4 can further be provided with spray means such as a swirl chamber connected via tangential swirl channels connecting to the duct 22.
In short, a conventional dispenser head is provided with a recess for receiving the plunger stem, with an outlet orifice connecting to said recess, with a push surface against which a finger is pressed, and with a peripheral skirt for masking the plunger stem.
That type of dispenser head is, in general, made of molded plastic. The mold necessary for manufacturing such a dispenser head essentially comprises three parts, namely a bottom core which defines the inside of the dispenser head and in particular the recess for receiving the plunger stem, a top shell which defines the outside portion of the head, and in particular the push surface and the outside wall of the peripheral skirt, and a pin that can be inserted through the top shell to define the annular space for receiving the insert and the duct 22 that causes the recess to communicate with the insert. The pin is inserted horizontally through the top shell while the join plane of the mold is defined at the bottom end of the peripheral skirt 28. It can thus be understood that it is not possible to vary the height of the peripheral skirt 28 since the distance between the join plane and the pin forming the annular space is fixed. Therefore, it is necessary to use a plurality of molds to manufacture dispenser heads having peripheral skirts of different heights for hiding the plunger stem, which gives rise to much higher investment cost.
An object of the present invention is to mitigate that problem of the prior art by defining a dispenser head in which the height of the peripheral skirt can be varied, without using a different mold for forming the body of the head.
In addition, since the dispenser head is made of a plastics material, shrinkage or sinking occurs locally, thereby locally affecting the visible surfaces of the head because of the unequal thicknesses in the plastics part. In particular, sink marks are often visible at the push top face of the head in the zone corresponding to the recess and to the duct. Such marks adversely affects the aesthetic appearance of the dispenser head. Another object of the present invention is thus to mitigate the visible effects of such sinking.
In addition, it is sometimes a requirement for the color of the dispenser head to match the color of fixing ring or of the container. In which case, it is necessary to color to the plastics material of which the dispenser head is made. Since the colorants used for tinting the plastics material are costly products, the cost of a colored dispenser head is also high. An object of the present invention is also to make it possible for colored dispenser heads to be made at lower cost.
To this end, the present invention provides a dispenser head designed to be mounted on the plunger stem of a dispenser device, such as a pump or a valve, for dispensing a fluid substance, said spray head comprising a body provided with a recess serving to receive the plunger stem, and with at least one duct causing said recess to communicate with a dispenser orifice, the body being received securely in an over-cap which covers it while leaving the recess unobstructed. The over-cap may be made of metal, but it is preferably made of a plastics material, and it solves all of the problems of the prior art related to the height of the peripheral skirt, to shrinkage, and to the color of the head. As regards the height of the peripheral skirt, it is easier and less costly to vary the height of the over-cap than to vary the height of the body of the head because the mold necessary to make the over-cap is much simpler. The body of the head thus becomes a standard element for a given head diameter, independently of the height of the head. A single body mold suffices for a head of a given diameter.
As regards shrinkage, it does not take place in an over-cap made of a plastics material given that the thickness of the wall thereof is uniform.
Finally, as regards the color of the head, given that the quantity of plastic necessary for molding the over-cap is less than the quantity necessary for molding a conventional body, a smaller quantity of colorant is necessary.
The Document FR-1 482 900 admittedly describes a pusher provided with a cover that covers internal members of the pusher defining a valve member. The cover is thus mounted to slide axially on the cap. The element making it possible to hold the cover on the cap is the insert which projects from the skirt of the cover. For this purpose, given that the cover is mounted to move relative to the insert, the opening through which the insert projects is overdimensioned to enable the cover to slide. In that plunger, the cover serves merely as an actuating wall for actuating the valve member so as to hold it closed until the pressure is released. The sliding characteristic is thus essential to the operation of that pusher.
Although that document describes a cover, it is not used for the same purposes, and, in addition, it is slidably mounted.
Depending on the embodiment, the dispensing orifice is formed by a spray jet-forming insert mounted on the body, the over-cap being provided with an opening for enabling the insert to pass through on mounting it on the body. In a variant, the dispensing orifice is formed in the over-cap.
In both cases, the head may include spray means in the form of a swirl chamber centered on the dispensing orifice and fed via at least two tangential swirl channels connecting to said at least one duct. In which case, the swirl chamber and the channels may be formed in the insert. In a variant, the swirl chamber and the channels may be formed in the body.
When the dispensing orifice is formed in the over-cap, and the swirl chamber and the swirl channels are formed in the body, it is not necessary to use a separate insert mounted on the body. A saving of one part and therefore of one corresponding mold is thus achieved. The over-cap then performs an additional function, namely the function of dispensing orifice.
In another embodiment, the body and the over-cap are provided with angular positioning means for determining the angular positioning of the over-cap relative to the body while they are being assembled, so that the spray orifice is centered on assembly relative to the swirl chamber. Advantageously, the inside of the over-cap forms an angular positioning and penetrating spike co-operating with a setback of corresponding shape provided in the body. The angular position of the over-cap on the body is thus set automatically on assembly.
The invention is described more fully below with reference to the accompanying drawings giving two embodiments of the present invention by way of non-limiting example.